| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.09 | 6.94 | 5.77 |
| 2024 | 6.08 | 6.97 | 5.02 |
| 2023 | 7.26 | 8.75 | 6.62 |
| 2022 | 7.68 | 9.36 | 6.49 |
| 2021 | 7.82 | 10.28 | 7.01 |
| 2020 | 8.57 | 13.99 | 2.96 |
| 2019 | 3.55 | 4.94 | 2.36 |
| 2018 | 3.1 | 4.02 | 2.23 |
| 2017 | 5.09 | 6.65 | 3.79 |
| 2016 | 5.38 | 6.26 | 4.11 |
| 2015 | 5.64 | 9.19 | 4 |
| 2014 | 4.25 | 6.11 | 3.08 |
| 2013 | 5.18 | 6.59 | 4.37 |
| 2012 | 5.47 | 6.19 | 4.45 |
| 2011 | 7.46 | 9.33 | 4.71 |
| 2010 | 7.88 | 9.64 | 6.42 |
| 2009 | 6.2 | 8.37 | 3.76 |
| 2008 | 5.79 | 10.35 | 2.67 |
| 2007 | 5.92 | 9.67 | 2.05 |
| 2006 | 1.42 | 2.29 | 0.85 |
| 2005 | 1.09 | 1.42 | 0.77 |
| 2004 | 1.88 | 2.81 | 1.35 |
| 2003 | 2.18 | 2.52 | 1.87 |
| 2002 | 2.8 | 3.27 | 2.49 |
| 2001 | 8.01 | 17.31 | 3.05 |
| 2000 | 7.77 | 11.59 | 4.99 |
| 1999 | 4.45 | 6.04 | 2.84 |